AC/DC coupling effects on low-IF tag-assisted mobile Doppler radar life sign detection

This paper investigates the AC and DC coupling effects in low-IF tag assisted continuous wave (CW) Doppler radar system. A low-IF RF tag device has been studied for motion artifact compensation in measuring vital sign using a mobile Doppler radar. This work presents a thorough investigation on coupling requirements of the amplifiers for signal conditioning of the received RF signal. Analysis and experiments were performed to achieve proper filtering of unwanted motion artifact from mobile baseband Doppler radar signal using adaptive filtering. This research work will benefit successful motion-artifact-compensation of mobile Doppler-radar life-sign device in vehicle, autonomous aerial vehicle, and in search and rescue robots.